Gas-heated once-through positive flow water heaters

ABSTRACT

A gas water heater has a heater shaft terminating in a fin block. A pair of exhaust hoods are used interchangeably on the water heater. Each of these hoods has a bottom portion fitting the top of the fin block. One of the hoods incorporates a backdraft-flow-preventing apparatus. The other incorporates a centrifugal blower with a vertical shaft and a vertically extending intake with a horizontally extending discharge.

United States Patent lnventors KarLErust Vaillant;

Helmut Schmidt; Robert Lehnartz, all of Remscheid, Germany Appl. No. 825,554 Filed May 19, 1969 Patented Aug. 24, 1971 Assignee Joli. Vaillant KG.

Remseheid, Germany Priority Aug. 2, 1968 GAS-HEATED ONCE-THROUGH POSITIVE FLOW WATER HEATERS 10 Claims, 10 Drawing Figs.

11.8. CI 122/494, 98/78, 110/162, l26/307A Int. Cl F2211 37/36 Field of Search 122/250,

[56] References Cited UNITED STATES PATENTS 3,211,080 10/1965 Rader 1. 110/162 3,361,127 H1968 Hein et al.. 126/307 3,347,147 10/1967 Howard 98/78 FORElGN PATENTS 890,694 3/1962 Great Britain 122/494 Primary Examinerl(enneth W. Sprague Attorney-Darbo, Robertson & Vandenbur'gh ABSTRACT: A gas water heater has a heater shaft terminating in a fin block. A pair of exhaust hoods are used interchangeably on the water heater. Each of these hoods has a bottom portion fitting the top of the fin block. One of the hoods incorporates a back-draft-flow-preventing apparatus. The other incorporates a centrifugal blower with a vertical shaft and a vertically extending intake with a horizontally extending discharge.

Patented Aug. 24, 1971 3,601,099

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Patented Aug. 24, 1971 5 Sheets-Sheet 5 GAS-HEATED ONCE-THROUGH POSITIVE FLOW WATER HEATERS The invention relates to gas-heated once-through positive flow water heaters having a fin block which terminates a heating shaft and an exhaust-gas-collecting hood adjoining the fin block and an exhaust gas blower. Normally, the exhaust-gascollecting hood of the apparatus is adjoined by a flow safety device which has a so-called top hood and is connected to the exhaust gas flue. In many cases the flow safety device is disposed within the casing of the apparatus. In other types of apparatus the flow safety device is disposed above the apparatus casing.

It is known in gas-heated once-through positive flow water heaters to employ and exhaust gas blower and to deliver the exhaust gas through a relatively small opening of the suspension wall to be discharged to atmosphere or into an exhaust gas flue,

The prior art also discloses so-called balanced flue apparatus which have a casing sealed relative to the room in which the apparatus is installed and in which the supply of fresh air and the discharge of exhaust gas is through two separate ducts provided in the suspension wall in the form of a brickwork box. In addition to the normal apparatus which are connected to a flue by means of a flow safety device, special types of apparatus whose construction differed substantially from each other were hitherto necessary for use with blower apparatus and for apparatus with an outside wall suspension (balanced flue).

The object of the invention is to provide a unified type of apparatus of a gas-heated once-through positive flow water heater which may be connected to a flue with a flow safety device but may also be operated with an exhaust gas blower and can be employed as an outside wall apparatus (balanced flue apparatus). This kind of standardization of apparatus types does not merely offer the advantage of simplified batch manufacture and storage but also offers the means to adapt the apparatus to prevailing spacial conditions and to the different conditions of aerodynamic lift resulting from the use of different types of gas.

According to the invention that is achieved in that the exhaust gas blower is constructed as a removable structural unit which may be exchanged with a flow safety device. While hitherto it was found that after installation of an apparatus there was insufficient aerodynamic lift, for example when using natural gas, or that an existing flue did not provide sufficient draft, the subsequent installation of an exhaust gas blower presents considerably difficulties. Unless it was preferred to employ a different type of apparatus specially designed for blower operation it was necessary, in order to install an exhaust gas blower, to perform complicated modifications which were not always successful. These difficulties are avoided according to the invention in that initially a blower extension is provided which is suitable for the apparatus and can easily installed and may be used immediately if necessary as an exchange component.

The exhaust gas blower together with the exhaust gas hood is constructed to form an integral exchangeable structural unit. This procedure is particularly recommended if in the interests of correct flow the exhaust gas hood with a built-in flow safety device must have another shape and dimensions than those required for blower operation. Under these conditions the means for fastening the exhaust gas hood to the rear wall ofthe apparatus cannot be identical.

An advantageous system is obtained if the exhaust gas blower, constructed integrally with a motor, rotates about a vertical axis and has a vertical suction branch and a horizontal delivery branch. The blower thus deflects the exhaust gases in the manner normally required. It is possible to arrange for the suction branch to have a mounting flange which can be bolted in different angular positions to a mating flange which is fixed relative to the apparatus. The exhaust gas blower may then be fitted so that the exhaust gas is discharged either to the rear or at an angle to the sides. In this way a greater degree of flexibility is obtained in installing the exhaust gas duct. The exhaust gas blower is advantageously disposed within a casing mounted on an apparatus rear wall. This procedure dispenses with the need for an addition cover for the blower and its motor and the apparatus will have a totally enclosed appearance. The apparatus rear wallmay be provided with one or more openings to accommodate exhaust gas lines connected to the discharge branch of the exhaust gas blower. Said openings may be blanked out when the apparatus rear wall is constructed or they may be only scribed so that they can be easily broken out as required on the installation site. i

In another embodiment of the invention the exhaust gas blower may be adapted for placing on the upper end face of the apparatus casing in which the discharge opening of the exhaust gas hood merges and may be covered by a hood-shaped blower casing. A flange connection which permits rotation of the exhaust gas blower is also provided in this case.

It is also possible to employ an exhaust gas blower having tangentially extending discharge branches. In such a case an inclined connecting pipe is appropriately provided between the suction branch of the exhaust gas blower and the mounting flange, said connecting pipe being so dimensioned that the central axis of a tangentially extending discharge branch of the exhaust gas blower is disposed perpendicularly over the central axis of the mounting flange. The discharge branch will then always remain radial relative to the connecting flange if the exhaust gas blower is mounted in a rotated position. In some cases it is advantageous if draft control means are provided between the discharge branch of the exhaust gas blower and the exhaust gas pipe to be connected thereto.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

FIGS. 1 and 2 show diagrammaticfront elevations and side elevations of a once-through positive flow water heater with a built-in flow safety device.

FIGS. 3 and 4 show in diagrammatic form the same apparatus after installation of an exhaust gas blower.

FIG. 5 is a diagrammatic plan view of FIG. 4.

FIGS. 6 and 7 show diagrammatic side elevations and plan views of another embodiment.

FIGS. 8 and 9 are diagrammatic plan views and front elevations of the arrangement of an exhaust gas blower having a tangential discharge socket.

FIG. 10 is a diagrammatic side elevation of a blower system with draft control means.

Referring to the drawings, a water control valve 3, a gas control valve 4, a gas burner 5, and a heater shaft 6, enclosed by a fin block 6 are provided on the rear wall 1 of a casing 2. An exhaust gas hood 7, adjoining the fin block 6'is retained by a support 12 which is mounted at 13 on the rear wall. Above the exhaust gas hood 7 are deflecting means 8, being part of the flow safety device, and a top hood 9, connectable to a flue which is not shown. In this respect the once-through positive flow water heater corresponds to the known, normal construction in which the back draft flow safety device comprising parts 7, 8 and 9, is disposed within the casing. As can be seen from FIGS. 3 and 4, the flow safety device comprising parts 7, 8 and 9 can be removed and can be replaced by an exhaust gas blower which is combined to form an integral structural unit with an exhaust gas hood 7' of different dimensions. The support 12 serves to mount the exhaust gas hood 7 on the casing rear wall 1. The exhaust gas blower 10 is constructed integrally with its motor 10' and has a vertical axis of rotation. The vertical suction branch 11 is provided with a flange ll'which is bolted to a mating flange 12 on the exhaust gas hood 7. The horizontal discharge branch 10" of the exhaust gas blower 10 is connected to an exhaust gas pipe 14 which extends through the wall on which the apparatus is mounted, to atmosphere. An opening 15 for admitting the exhaust gas pipe 14 is provided in the casing rear wall 1. As indicated in FIG. 5,

the flanges l 1' and 12' can be coupled or bolted to each other in different angular positions so that the discharge branch can point in different directions and may therefore also be connected to laterally extending exhaust gas ducts 14 or 14'.

In the once-through positive flow water heater illustrated in FIGS. 6 and 7, the casing 2'terminates at the level of an exhaust gas hood 7" whose discharge openings merges into the upper end face of the casing 2. The flange 11 of the exhaust gas blower 10 is bolted to a mating flange 12 on the exhaust gas hood 7". As shown in FIG. 7, the exhaust gas blower 10 can also be fitted in different angular positions so that the exhaust gas branch 10" can point in different directions. The exhaust gas blower 10 and its motor 10' are covered by a hoodshaped casing 16.

In the embodiment illustrated in FIGS. 8 and 9 an exhaust gas blower 17 is provided having a tangentially extending discharge branch 17 An inclined pipe connecting member 19 is disposed between the suction branch 18 and the flange 1 1 so that the exhaust gas blower 17 is disposed eccentrically relative to the mounting flange 1 1'. The pipe connecting piece 19 is so designed that the center line of the discharge branch 17 is disposed perpendicularly above the center of the flange 11'. If the exhaust gas blower 17 is bolted on in the manner described hereinabove in different angular positions, the discharge branch 17" remains radial to the flange 11' in any angular position. The mating flange 12' is disposed on the exhaust gas hood 7 as in the embodiment illustrated in FIGS. 3 and 4.

In FIG. 10 a flared exhaust gas pipe 14 is provided, having an expanded section 20 into which the discharge branch 10"retained by webs 21, of the exhaust gas blower 10 is adapted to extend. This system interrupts the exhaust gas duct 14 in the manner of a known draft control system. If the exhaust gas discharge is substantially obstructed it is therefore possible for part of the exhaust gases to enter into the room in which the apparatus is installed without however being able to enter the combustion chamber.

We claim:

I. In an apparatus including a gas-heated once-through positive flow water heater having a heater shaft terminating in a fin block, the improvement comprising in combination therewith:

a pair of interchangeable exhaust gas hoods of a size to fit said fin block and usable one at a time on said fln block; back draft flow safety means incorporating one of said hoods; and

exhaust gas blower means incorporating the other of said hoods;

whereby the heater may readily be adapted for use in different types of installation,

2. In an apparatus as set forth in claim 1, wherein said blower means includes an exhaust gas blower having an integral motor, said blower and motor having a shaft rotating about a vertical axis, said blower having a vertical suction branch communicating with the respective hood and a horizontal discharge branch.

3. In an apparatus as set forth in claim 2, wherein :ald respective hood has a mounting flange at the top thereof; and said blower has a mounting flange at the bottom thereof about said suction branch with the blower flange being positioned on the hood flange; said flanges having means to connect the flanges at different angular positions with respect to each other.

4. In an apparatus as set forth in claim 3, including a casing about said heater, which casing has a rear wall, said blower being within said casing and including means to mount the blower on said rear wall.

5. In an apparatus as set forth in claim 4 and for use with an exhaust gas duct, wherein said rear wall has means to provide a plurality of openings to admit said duct for communication with said discharge branch at different angular positions with res ect to said casing.

In an apparatus as set forth in claim 5, wherein said respective hood defines a vertical axis, said suction branch being inclined towards one side of said axis, said discharge branch being substantially horizontal and having an axis intersecting said hood axis.

7. In an apparatus as set forth in claim 6, including draft control means between said discharge branch and said duct.

8. In an apparatus as set forth in claim 2 and for use with an exhaust gas duct, and including a casing about said heater, which casing has a rear wall, said rear wall having means to provide a plurality of openings to admit said duct for communication with said discharge branch at different angular positions with respect to said casing.

9. In an apparatus as set forth in claim 8, wherein said respective hood defines a vertical axis, said suction branch being inclined towards one side of said axis, said discharge branch being substantially horizontal and having an axis intersecting said hood axis.

10. In an apparatus as set forth in claim 2, including a casing about said heater, which casing has an upper end wall with an opening therethrough, said respective hood being within said casing and extending upwardly from said block toward said opening, said blower being releasably mounted on said wall with said suction branch communicating with said hood through said opening, and a hood-shaped blower casing covering said blower. 

1. In an apparatus including a gas-heated once-through positive flow water heater having a heater shaft terminating in a fin block, the improvement comprising in combination therewith: a pair of interchangeable exhaust gas hoods of a size to fit said fin block and usable one at a time on said fin block; back draft flow safety means incorporating one of said hoods; and Exhaust gas blower means incorporating the other of said hoods; whereby the heater may readily be adapted for use in different types of installation.
 2. In an apparatus as set forth in claim 1, wherein said blower means includes an exhaust gas blower having an integral motor, said blower and motor having a shaft rotating about a vertical axis, said blower having a vertical suction branch communicating with the respective hood and a horizontal discharge branch.
 3. In an apparatus as set forth in claim 2, wherein said respective hood has a mounting flange at the top thereof; and said blower has a mounting flange at the bottom thereof about said suction branch with the blower flange being positioned on the hood flange; said flanges having means to connect the flanges at different angular positions with respect to each other.
 4. In an apparatus as set forth in claim 3, including a casing about said heater, which casing has a rear wall, said blower being within said casing and including means to mount the blower on said rear wall.
 5. In an apparatus as set forth in claim 4 and for use with an exhaust gas duct, wherein said rear wall has means to provide a plurality of openings to admit said duct for communication with said discharge branch at different angular positions with respect to said casing.
 6. In an apparatus as set forth in claim 5, wherein said respective hood defines a vertical axis, said suction branch being inclined towards one side of said axis, said discharge branch being substantially horizontal and having an axis intersecting said hood axis.
 7. In an apparatus as set forth in claim 6, including draft control means between said discharge branch and said duct.
 8. In an apparatus as set forth in claim 2 and for use with an exhaust gas duct, and including a casing about said heater, which casing has a rear wall, said rear wall having means to provide a plurality of openings to admit said duct for communication with said discharge branch at different angular positions with respect to said casing.
 9. In an apparatus as set forth in claim 8, wherein said respective hood defines a vertical axis, said suction branch being inclined towards one side of said axis, said discharge branch being substantially horizontal and having an axis intersecting said hood axis.
 10. In an apparatus as set forth in claim 2, including a casing about said heater, which casing has an upper end wall with an opening therethrough, said respective hood being within said casing and extending upwardly from said block toward said opening, said blower being releasably mounted on said wall with said suction branch communicating with said hood through said opening, and a hood-shaped blower casing covering said blower. 